<?php
class author extends base {
    /**
     * Name of the author
     * @var string
     * @orm char(128)
     */
    public $first_name;

    /**
     * Name of the author
     * @var string
     * @orm char(128)
     */
    public $last_name;

    /**
     * Constructor
     * @param string $name author name
     */
    public function __construct($first_name = '', $last_name = '') {
        parent::__construct();
        $this->first_name = $first_name;
        $this->last_name = $last_name;
    }

    // the rest of the code in the class omitted...

}